-- | -- Module: Data.Reify.Graph -- Copyright: (c) 2009 Andy Gill -- License: BSD3 -- -- Maintainer: Andy Gill <andygill@ku.edu> -- Stability: unstable -- Portability: ghc -- -- This is the shared definition of a 'Graph' in Data.Reify. {-# LANGUAGE FlexibleContexts, UndecidableInstances #-} module Data.Reify.Graph ( Graph(..), Unique ) where -- | 'Graph' is a basic graph structure over nodes of the higher kind 'e', with a single root. -- There is an assumption that there is no Unique used in a node which does not have a -- corresponding entry is the association list. -- The idea with this structure is that it is trivial to convert into an 'Array', -- 'IntMap', or into a Martin Erwig's Functional Graph, as required. data Graph e = Graph [(Unique,e Unique)] Unique type Unique = Int -- | If 'e' is s Functor, and 'e' is 'Show'-able, then we can 'Show' a 'Graph'. instance (Show (e Int)) => Show (Graph e) where show (Graph netlist start) = "let " ++ show [ (u,e) | (u,e) <- netlist ] ++ " in " ++ show start